Home-use applicators for non-invasively removing heat from subcutaneous lipid-rich cells via phase change coolants

ABSTRACT

Home-use applicators for non-invasively removing heat from subcutaneous, lipid-rich cells via phase change coolants, and associated devices, systems and methods. A device in accordance with a particular embodiment includes an applicator releasably positionable in thermal communication with human skin, and a coolant vessel having a coolant. The device further includes a heat transfer conduit operatively coupled to the applicator and housing a heat transfer fluid that is isolated from fluid contact with the coolant. A heat exchanger is operatively coupled between the coolant vessel and the heat transfer conduit to transfer heat between the heat transfer fluid and the coolant, and a fluid driver is operatively coupled to the heat transfer conduit to direct the heat transfer fluid between the applicator and the heat exchanger.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to the following U.S.Provisional Patent Applications, each of which is incorporated herein byreference: 61/298,175, filed Jan. 25, 2010 and 61/354,615, filed Jun.14, 2010. To the extent that the materials in the foregoing referencesand/or any other references incorporated herein by reference conflictwith the present disclosure, the present disclosure controls.

TECHNICAL FIELD

The present application relates generally to home-use applicators fornon-invasively removing heat from subcutaneous lipid-rich cells viaphase change coolants, and associated devices, systems and methods. Inparticular, several embodiments are directed to devices that a user mayeasily recharge or regenerate using a conventional commercial, clinical,institutional or domestic freezer.

BACKGROUND

Excess body fat, or adipose tissue, may be present in various locationsof the body, including, for example, the thighs, buttocks, abdomen,knees, back, face, arms, chin, and other areas. Moreover, excess adiposetissue is thought to magnify the unattractive appearance of cellulite,which forms when subcutaneous fat protrudes into the dermis and createsdimples where the skin is attached to underlying structural fibrousstrands. Cellulite and excessive amounts of adipose tissue are oftenconsidered to be unappealing. Moreover, significant health risks may beassociated with higher amounts of excess body fat.

A variety of methods have been used to treat individuals having excessbody fat and, in many instances, non-invasive removal of excesssubcutaneous adipose tissue can eliminate unnecessary recovery time anddiscomfort associated with invasive procedures such as liposuction.Conventional non-invasive treatments for removing excess body fattypically include topical agents, weight-loss drugs, regular exercise,dieting or a combination of these treatments. One drawback of thesetreatments is that they may not be effective or even possible undercertain circumstances. For example, when a person is physically injuredor ill, regular exercise may not be an option. Similarly, weight-lossdrugs or topical agents are not an option when they cause an allergic orother negative reaction. Furthermore, fat loss in selective areas of aperson's body often cannot be achieved using general or systemicweight-loss methods.

Other methods designed to reduce subcutaneous adipose tissue includelaser-assisted liposuction and mesotherapy. Newer non-invasive methodsinclude applying radiant energy to subcutaneous lipid-rich cells via,e.g., radio frequency and/or light energy, such as is described in U.S.Patent Publication No. 2006/0036300 and U.S. Pat. No. 5,143,063, or via,e.g., high intensity focused ultrasound (HIFU) radiation such as isdescribed in U.S. Pat. Nos. 7,258,674 and 7,347,855. In contrast,methods and devices for non-invasively reducing subcutaneous adiposetissue by cooling are disclosed in U.S. Pat. No. 7,367,341 entitled“METHODS AND DEVICES FOR SELECTIVE DISRUPTION OF FATTY TISSUE BYCONTROLLED COOLING” to Anderson et al. and U.S. Patent Publication No.2005/0251120 entitled “METHODS AND DEVICES FOR DETECTION AND CONTROL OFSELECTIVE DISRUPTION OF FATTY TISSUE BY CONTROLLED COOLING” to Andersonet al., the entire disclosures of which are incorporated herein byreference.

BRIEF DESCRIPTION OF THE DRAWINGS

Many features of the present technology are illustrated in simplified,schematic and/or partially schematic formats in the following Figures toavoid obscuring significant technology features. Many features are notdrawn to scale so as to more clearly illustrate these features.

FIG. 1 is a partially schematic, partially cut-away illustration of acooling device having a coolant vessel and heat exchanger configured inaccordance with an embodiment of the disclosure.

FIG. 2 is a partially schematic, partially cut-away illustration of aparticular embodiment of the device shown in FIG. 1.

FIG. 3 is a partially schematic illustration of a device having anoverall arrangement generally similar to that shown in FIG. 1,configured in accordance with still another embodiment of thedisclosure.

FIG. 4 is a partially schematic illustration of a device having a heatexchanger and a removable coolant vessel configured in accordance withanother embodiment of the disclosure.

FIG. 5A is a partially schematic, enlarged illustration of an embodimentof the coolant vessel and heat exchanger shown in FIG. 4.

FIG. 5B is a partially schematic, cross-sectional illustration of theheat exchanger and coolant vessel taken substantially along line 5B-5Bof FIG. 5A.

FIG. 6A is a partially schematic, partially cut-away illustration of acoolant vessel and heat exchanger configured in accordance with anotherembodiment of the disclosure.

FIG. 6B is a partially schematic, cross-sectional illustration of anembodiment of the heat exchanger and coolant vessel, taken substantiallyalong line 6B-6B of FIG. 6A.

FIG. 7 is a partially schematic illustration of a device having acoolant vessel and heat exchanger that are separable from an applicatorin accordance with yet another embodiment of the disclosure.

FIG. 8 is a partially schematic illustration of a portion of the coolantvessel and heat exchanger, taken substantially along line 8-8 of FIG. 7.

FIG. 9 is a partially schematic, cross-sectional illustration of anapplicator having non-elastic and elastic materials arranged inaccordance with an embodiment of the disclosure.

FIG. 10 is a partially schematic, cross-sectional illustration of anapplicator having an internal support structure in accordance with anembodiment of the disclosure.

FIG. 11 is an enlarged illustration of a portion of the applicator shownin FIG. 10.

DETAILED DESCRIPTION 1. Overview

Several examples of devices, systems and methods for coolingsubcutaneous adipose tissue in accordance with the presently disclosedtechnology are described below. Although the following descriptionprovides many specific details of the following examples in a mannersufficient to enable a person skilled in the relevant art to practice,make and use them, several of the details and advantages described belowmay not be necessary to practice certain examples and methods of thetechnology. Additionally, the technology may include other examples andmethods that are within the scope of the claims but are not describedhere in detail.

References throughout this specification to “one example,” “an example,”“one embodiment” or “an embodiment” mean that a particular feature,structure, or characteristic described in connection with the example isincluded in at least one example of the present technology. Thus, theoccurrences of the phrases “in one example,” “in an example,” “oneembodiment” or “an embodiment” in various places throughout thisspecification are not necessarily all referring to the same example.Furthermore, the particular features, structures, routines, steps orcharacteristics may be combined in any suitable manner in one or moreexamples of the technology. The headings provided herein are forconvenience only and are not intended to limit or interpret the scope ormeaning of the claimed technology.

Certain embodiments of the technology described below may take the formof computer-executable instructions, including routines executed by aprogrammable computer or controller. Those skilled in the relevant artwill appreciate that the technology can be practiced on computer orcontroller systems other than those shown and described below. Thetechnology can be embodied in a special-purpose computer, controller, ordata processor that is specifically programmed, configured orconstructed to perform one or more of the computer-executableinstructions described below. Accordingly, the terms “computer” and“controller” as generally used herein refer to any data processor andcan include internet appliances, hand-held devices, multi-processorsystems, programmable consumer electronics, network computers, minicomputers, and the like. The technology can also be practiced indistributed environments where tasks or modules are performed by remoteprocessing devices that are linked through a communications network.Aspects of the technology described below may be stored or distributedon computer-readable media, including magnetic or optically readable orremovable computer discs as well was media distributed electronicallyover networks. In particular embodiments, data structures andtransmissions of data particular to aspects of the technology are alsoencompassed within the scope of the present technology. The presenttechnology encompasses both methods of programming computer-readablemedia to perform particular steps, as well as executing the steps.

One embodiment of a cooling device for cooling subcutaneous lipid-richcells in a human includes an applicator that is releasably positionablein thermal communication with human skin. The device further includes acoolant vessel having a coolant and a heat transfer conduit having aheat transfer fluid that is isolated from fluid contact with thecoolant. A heat exchanger is operatively coupled between the coolantvessel and heat transfer conduit to transfer heat between the heattransfer fluid and the coolant, and a fluid driver is operativelycoupled to the heat transfer conduit to direct the heat transfer fluidbetween the applicator and the heat exchanger.

In a further particular embodiment, the coolant has a liquid/solid phasetransition temperature greater than the liquid/solid phase transitiontemperature of the heat transfer fluid. The heat exchanger is positionedwithin the coolant vessel and includes a heat exchanger conduit that,together with the heat transfer conduit and the applicator, form asealed, closed-loop path for the heat transfer fluid. Accordingly, theentire device can be placed in a freezer (e.g., a domestic freezer) tofreeze the coolant in preparation for treating lipid-rich cells in ahuman. In other embodiments, only selected components of the device areremovable to freeze or otherwise cool the coolant.

A method for cooling human tissue in accordance with a particularembodiment of the disclosure includes releasably attaching an applicatorto a human, and removing heat from subcutaneous lipid-rich tissue of thehuman via the applicator to selectively reduce lipid-rich cells of thetissue (e.g., via the body's reaction to cooling). The heat is removedby directing a chilled heat transfer fluid to applicator andtransferring absorbed heat from the heat transfer fluid to a coolant. Inparticular embodiments, the coolant can remain solid, remain liquid orchange phase from a solid to a liquid as it receives heat from the heattransfer fluid. The method still further includes re-cooling thecoolant. Selected methods in accordance with another embodiment of thedisclosure include removing the heat by directing a chilled heattransfer fluid into a flexible envelope and through a porous internalsupport structure within the envelope, while the porous internalstructure at least restricts fluid pressure in the envelope from (a)bulging the envelope outwardly, or (b) collapsing the internalstructure, or (c) both (a) and (b). Still another method includesdirecting the chilled heat transfer fluid into an applicator, betweentwo flexible portions of the applicator, each having a differentelasticity.

Without being bound by theory, the selective effect of cooling onlipid-rich cells is believed to result in, for example, membranedisruption, cell shrinkage, disabling, damaging, destroying, removing,killing or other methods of lipid-rich cell alteration. Such alterationis believed to stem from one or more mechanisms acting alone or incombination. It is thought that such mechanism(s) trigger an apoptoticcascade, which is believed to be the dominant form of lipid-rich celldeath by non-invasive cooling. In any of these embodiments, the effectof tissue cooling is to selectively reduce lipid-rich cells.

Apoptosis, also referred to as “programmed cell death”, is agenetically-induced death mechanism by which cells self-destruct withoutincurring damage to surrounding tissues. An ordered series ofbiochemical events induce cells to morphologically change. These changesinclude cellular blebbing, loss of cell membrane asymmetry andattachment, cell shrinkage, chromatin condensation and chromosomal DNAfragmentation. Injury via an external stimulus, such as cold exposure,is one mechanism that can induce cellular apoptosis in cells. Nagle, W.A., Soloff, B. L., Moss, A. J. Jr., Henle, K. J. “Cultured ChineseHamster Cells Undergo Apoptosis After Exposure to Cold but NonfreezingTemperatures” Cryobiology 27, 439-451 (1990).

One aspect of apoptosis, in contrast to cellular necrosis (a traumaticform of cell death causing local inflammation), is that apoptotic cellsexpress and display phagocytic markers on the surface of the cellmembrane, thus marking the cells for phagocytosis by macrophages. As aresult, phagocytes can engulf and remove the dying cells (e.g., thelipid-rich cells) without eliciting an immune response. Temperaturesthat elicit these apoptotic events in lipid-rich cells may contribute tolong-lasting and/or permanent reduction and reshaping of subcutaneousadipose tissue.

One mechanism of apoptotic lipid-rich cell death by cooling is believedto involve localized crystallization of lipids within the adipocytes attemperatures that do not induce crystallization in non-lipid-rich cells.The crystallized lipids selectively may injure these cells, inducingapoptosis (and may also induce necrotic death if the crystallized lipidsdamage or rupture the bi-lipid membrane of the adipocyte). Anothermechanism of injury involves the lipid phase transition of those lipidswithin the cell's bi-lipid membrane, which results in membranedisruption or disfunction, thereby inducing apoptosis. This mechanism iswell-documented for many cell types and may be active when adipocytes,or lipid-rich cells, are cooled. Mazur, P., “Cryobiology: the Freezingof Biological Systems” Science, 68: 939-949 (1970); Quinn, P. J., “ALipid Phase Separation Model of Low Temperature Damage to BiologicalMembranes” Cryobiology, 22: 128-147 (1985); Rubinsky, B., “Principles ofLow Temperature Preservation” Heart Failure Reviews, 8, 277-284 (2003).Another mechanism of injury may involve a disfunction of ion transferpumps across the cellular membrane to maintain desired concentrations ofions such as potassium (K+) or sodium (Na+). An ion imbalance across thecell membrane may result from lipid phase transition of lipids withinthe cell's bi-lipid membrane or by another mechanism, thereby inducingapoptosis. Other yet-to-be-understood apoptotic mechanisms may exist,based on the relative sensitivity to cooling of lipid-rich cellscompared to non-lipid rich cells.

In addition to the apoptotic mechanisms involved in lipid-rich celldeath, local cold exposure is also believed to induce lipolysis (i.e.,fat metabolism) of lipid-rich cells and has been shown to enhanceexisting lipolysis which serves to further increase the reduction insubcutaneous lipid-rich cells. Vallerand, A. L., Zamecnik. J., Jones, P.J. H., Jacobs, I. “Cold Stress Increases Lipolysis, FFA Ra and TG/FFACycling in Humans” Aviation, Space and Environmental Medicine 70, 42-50(1999).

One expected advantage of the foregoing techniques is that thesubcutaneous lipid-rich cells can be reduced generally withoutcollateral damage to non-lipid-rich cells in the same region. Ingeneral, lipid-rich cells can be affected at low temperatures that donot affect non-lipid-rich cells. As a result, lipid-rich cells, such asthose associated with cellulite, can be affected while other cells inthe same region are generally not damaged even though the non-lipid-richcells at the surface may be subjected to even lower temperatures thanthose to which the lipid-rich cells are exposed.

2. Representative Devices and Methods that Include Applicators, CoolantVessels, and Heat Exchangers Arranged as a Single Unit

FIG. 1 is a partially schematic, partially cut-away illustration of adevice 100 having an applicator 120 operatively coupled to a coolantvessel 140 to cool human tissue 110. In particular, the device 100 isconfigured to cool a subcutaneous, lipid-rich tissue 112, withoutdamaging the overlying dermis 111, generally in the manner describedabove. The applicator 120 is coupled to the coolant vessel 140 by a heattransfer conduit 150 that carries a heat transfer fluid 155.Accordingly, the heat transfer conduit 150 includes a supply portion 151a that directs the heat transfer fluid 155 to the applicator 120, and areturn portion 151 b that receives heat transfer fluid 155 exiting theapplicator 120. The heat transfer fluid 155 is propelled through theheat transfer conduit 150 by a fluid driver 170, e.g., a pump or othersuitable device. The heat transfer conduit 150 is typically insulated toprevent the ambient environment from heating the heat transfer fluid155. Other elements of the device (aside from the cooling surface of theapplicator 120 in contact with the tissue 110) are also insulated fromthe ambient environment to prevent heat loss and frost formation.

The heat transfer conduit 150 is connected to a heat exchanger 160having a heat exchanger conduit (e.g., tubing) 161 that is positionedwithin or at least partially within the coolant vessel 140. The coolantvessel 140 contains a coolant 141 that is in close thermal contact withthe heat exchanger 160, but is isolated from direct fluid contact withthe heat transfer fluid 155 contained within the heat exchanger tubing161. Accordingly, the heat exchanger 160 facilitates heat transferbetween the heat transfer fluid 155 and the coolant 141, whilepreventing these fluids from mixing. As a result, the coolant 141 can beselected to have a composition different than that of the heat transferfluid 155. In particular embodiments, the coolant 141 can be selected tohave a phase transition temperature (from liquid/gel to solid) that isless than normal body temperature (about 37° C.) and in particularembodiments, in the range of from about 37° C. to about −20° C., orabout 25° C. to about −20° C., or about 0° C. to about −12° C., or about−3° C. to about −6° C., to present a constant temperature environment tothe heat transfer fluid 155 as the coolant 141 transitions from a solidto a liquid/gel. The heat transfer fluid 155 in such embodiments has aphase transition temperature that is less than that of the coolant 141.Accordingly, the heat transfer fluid 155 remains in a fluid state evenwhen the coolant 141 or a portion of the coolant 141 is in a solidstate. As a result, the heat transfer fluid 155 can flow within the heattransfer conduit 150 to convey heat away from the human tissue 110 evenwhen the coolant 141 is frozen or at least partially frozen.

In operation, the device 100 can be prepared for use by placing themajor components (e.g., the applicator 120, the heat transfer conduit150, the heat exchanger 160 and the coolant vessel 140), as a unit, in asuitably cold environment. In a particular embodiment, the coldenvironment includes a freezer (e.g., a domestic freezer), in which thetemperature typically ranges from about −10° C. to about −20° C.,sufficient to freeze the coolant 141. After the coolant 141 is frozen,the device 100 can be removed from the freezer or other coldenvironment, as a unit, and the applicator 120 can be attached to thehuman tissue 110 using a cuff or other suitable attachment device (e.g.,having a Velcro® closure, a buckle, or other releasable feature).Optionally, the user can apply a lotion between the applicator 120 andthe skin to facilitate heat transfer and/or provide a moisturizing orother cosmetic effect. Whether or not the user applies a lotion oranother intermediate constituent, the applicator 120 is positioned inthermal communication with the user's skin, so as to effectively removeheat from the lipid-rich tissue 112. The fluid driver 170 is thenactivated to drive the heat transfer fluid 155 through the heat transferconduit 150, thus transferring heat from the subcutaneous lipid-richtissue 112 to the frozen coolant 141 via the heat exchanger 160. As thecoolant 141 melts, the temperature within the coolant vessel 140 remainsapproximately constant so as to provide a constant or nearly constantheat transfer fluid temperature to the human tissue 110. After the humantissue 110 has been cooled for an appropriate period of time, causingsome or all of the coolant 141 to melt, the device 100 can be removed asa unit from the human tissue 110, as indicated by arrow A, and thecoolant 141 can be re-frozen by placing the device 100 in the freezer.Accordingly, the cooling capacity of the coolant vessel 140 can bereadily recharged or regenerated prior to a subsequent treatmentprocess. The appropriate tissue-cooling period of time can be controlledby properly selecting the cooling capacity of the coolant 141, or via acontroller and/or sensor, as described in further detail later withreference to FIG. 2.

In particular embodiments described above with reference to FIG. 1 andbelow with reference to FIGS. 2-8, the coolant 141 changes phase as itis heated by the heat transfer fluid 155, and then changes back againwhen it is cooled. In other embodiments, the coolant 141 can be heatedand cooled without undergoing phase changes. For example, the coolant141 can remain in a solid phase throughout both the heating and coolingprocesses, or can remain in a liquid phase throughout both processes. Insuch cases, the cooling process (whether it takes place in a freezer orother environment) does not freeze the coolant. When the coolant 141remains a solid, its phase transition temperature is above that of theheat transfer fluid. When the coolant 141 remains a liquid, its phasetransition temperature can be above, below, or equal to that of the heattransfer fluid 155. In such cases, the heat transfer fluid 155 and thecoolant 141 can have different or identical compositions, whileremaining isolated from direct fluid contact with each other.

FIG. 2 is a partially schematic, partially cut-away illustration of anembodiment of the device 100 that operates in accordance with thegeneral principles described above with reference to FIG. 1.Accordingly, the device 100 shown in FIG. 2 includes an applicator 120and a coolant vessel 140 thermally connected to the applicator 120 via aheat exchanger 160 and a heat transfer conduit 150.

One characteristic of the device 100 shown in both FIG. 1 and FIG. 2 isthat the when the applicator 120 is first placed against the humantissue 110, the heat transfer fluid 155 in the heat transfer conduit 150and the applicator 120 will be at or approximately at the temperature ofthe cold environment in which the device 100 was placed. In at leastsome cases, this temperature may be uncomfortably low. Accordingly, thedevice 100 and associated methods can include features for reducing thelikelihood that the user will encounter a potentially detrimental effector uncomfortably cold sensation when first using the device 100. In aparticular embodiment, the device 100 can include a heater 152positioned to heat the heat transfer fluid 155 entering the applicator120 via the supply portion 151 a. This arrangement can increase thetemperature of the heat transfer fluid 155 by at least an amountsufficient to reduce the user's discomfort and/or provide a safe andefficacious treatment. In a further particular aspect of thisembodiment, the device 100 can be configured to shunt the heat transferfluid 155 away from the heat exchanger 160 while the heat transfer fluidtemperature is initially elevated. This arrangement can avoidunnecessarily melting the coolant 141 before treatment begins.Accordingly, the device 100 can include a shunt channel 153 connectedbetween the supply portion 151 a and the return portion 151 b inparallel with the heat exchanger 160 to bypass the heat exchanger 160.One or more shunt valves 154 (two are shown in FIG. 2) are positioned toregulate flow through the shunt channel 153, e.g., to open or partiallyopen the shunt channel 153 during initial startup, and then close orpartially close the shunt channel 153 after the temperature of theapplicator 120 has been elevated by a sufficient amount.

The device 100 can include a controller 180 to control the heater 152,the shunt valves 154, and/or other features of the device 100. Forexample, in a particular embodiment, the controller 180 includes amicroprocessor 183 having a timer component 184. When the device 100 isinitially powered (e.g., by activating the fluid driver 170), themicroprocessor 183 can automatically open the shunt channel 153 via theshunt valves 154, and activate the heater 152. The heater 152 and theshunt channel 153 can remain in this configuration for a predeterminedtime, after which the microprocessor 153 automatically issues controlsignals deactivating the heater 152 and closing the shunt channel 153.Accordingly, the timer component 184 operates as a sensor by sensing thepassage of time during which the heater 152 is actively heating the heattransfer fluid 155. In other embodiments described further below, one ormore sensors can detect other characteristics associated with the device100.

In a particular embodiment, the microprocessor 183 can direct thecontrol signals 182 based on inputs 181 received from one or moretemperature sensors 186. For example, the device 100 can include a firsttemperature sensor 186 a positioned at the applicator 120. Themicroprocessor 183 can automatically activate the heater 152 and theshunt channel 153 until the first temperature sensor 186 a indicates atemperature suitable for placing the applicator 120 against the humantissue 110. The device 100 can include a second temperature sensor 186 blocated at the coolant vessel 140 (e.g., the center of the coolant 141).The microprocessor 183 can accordingly direct control signals 182 thatactivate the fluid driver 170 for as long as the second temperaturesensor 186 b indicates a constant and/or suitably low temperature. Whenthe second temperature sensor 186 b identifies a temperature rise(indicating that the coolant 141 has completely melted), themicroprocessor 183 can automatically deactivate the fluid driver 170. Ifthe coolant 141 is not selected to change phase during heating andcooling, the micro-processor 183 can deactivate the fluid driver 170when the temperature of the coolant 141 exceeds a threshold temperature.The controller 180 can include an output device 185 that indicates theoperational modes or states of the device 100. For example, the outputdevice 185 can display visual signals (e.g., via different colored LEDs)and/or aural signals (e.g., via an audio speaker) to signify when theapplicator 120 is ready to be applied to the human tissue 110, when thetreatment program is over, and/or when temperatures or othercharacteristics of any of the device components are outside pre-selectedbounds.

In yet another embodiment, the controller 180 can direct a simplifiedprocess for handling the initial temperature of the heat transfer fluid155. In particular, the controller 180 can monitor the temperaturesignal provided by the first temperature sensor 186 a, withoutactivating the fluid driver 170, and without the need for the heater 152or the shunt channel 153. Instead, the controller 180 can generate anoutput (presented by the output device 185) when the ambient conditionscause the heat transfer fluid 155 to rise to an acceptable temperature,as detected by the first temperature sensor 186 a. The user canoptionally accelerate this process by applying heat to the applicator120 and/or the heat transfer conduit 150 via an external heat source. Anadvantage of this approach is that it can be simpler than the integratedheater 152 described above. Conversely, the heater 152 (under thedirection of the controller 180) can be more reliable and quicker, atleast in part because the heater 152 is positioned within the insulationprovided around the heat transfer conduit 150 and other devicecomponents.

The device 100 can include a variety of features configured to enhanceuniform heat distribution and heat transfer. For example, the heatexchanger 160 can include fins 165 on the heat exchanger tubing 161 toincrease the surface area available to transfer heat between the heattransfer fluid 155 and the coolant 141. The coolant vessel 140 can alsoinclude a first agitator 101 a that distributes the melting coolant 141within the coolant vessel 140 to provide for a more uniform temperatureand heat transfer rate within the vessel 140. In one embodiment, thefirst agitator 101 a can include a magnetically driven device, and canbe magnetically coupled to a first actuator motor 102 a positionedoutside the coolant vessel 140. Accordingly, the agitator 101 a canoperate without the need for a sealed drive shaft penetrating into thecoolant vessel 140. A similar arrangement can be used at the applicator120. In particular, the applicator 120 can include a second agitator 101b driven by a second actuator motor 102 b to distribute the heattransfer fluid 155 uniformly within the applicator 120. Suitablypositioned internal fluid channels can be used in addition to or in lieuof the second agitator 101 b to uniformly distribute the heat transferfluid 155 in the applicator 120. A representative device that includessuch features is a Model No. 10240 pad, available from Breg Polar Care(bregpolarcare.com). The actuator motors 102 a, 102 b can be operativelycoupled to a power cord 173, which also provides power to the fluiddriver 170 and the heater 152. In other embodiments, the device 100 caninclude other elements that agitate and/or distribute the fluid in theapplicator 120 and/or the coolant vessel 140. Such elements can includeliquid jets, shaft-driven stirrers, pistons and/or other devices thatmove the solid and/or liquid portion of the coolant 141 within thecoolant vessel 140, and/or actuators that vibrate, shake, tip orotherwise move the coolant vessel 140 itself or heat exchanger 160within the coolant vessel.

As noted above, the applicator 120, the heat transfer conduit 150, theheat exchanger 160, and the coolant vessel 140 can be moved as a unitbetween the target tissue 110 and a freezer or other cold environmentprior to and after treatment. In a particular embodiment, the remainingcomponents or elements of the device 100 shown in FIG. 2 can also beplaced in the freezer. For example, when the fluid driver 170 includes apump 171 driven by a pump motor 172, these components (along with thecontroller 180) can also be placed in the freezer. In other embodiments,one or more of these components may be removed prior to placing the restof the device 100 in the freezer. For example, the power cord 173 can beremoved from the motor 172 and other system components at a junction B1as indicated by arrow B. In another embodiment, the pump motor 172 canbe removed from the device 100 at a junction Cl as indicated by arrow C.For example, the pump motor 172 can be magnetically coupled to the pump171, generally in the manner of the stirrers described above to makeconnecting and disconnecting the motor 172 easier. In still anotheraspect of this embodiment, the controller 180 and/or components of thecontroller 180 can be carried by the motor 172 and can accordingly beremoved from the device 100 along with the motor 172.

Certain features described above in the context of a processor-basedautomatic control system can, in other embodiments, operate without aprocessor, or can operate manually. For example, the shunt valves 154can include thermostatic radiator values, or similar valves that have anintegrated temperature sensor (e.g., a mechanical thermostat) thatautonomously drives the valve without the need for a processor. In otherembodiments, the coolant 141 can change color as it undergoes its phasechange, which can eliminate the need for the second temperature sensor186 b. In one aspect of this embodiment, the coolant vessel 140 istransparent, allowing the user to readily see both when the coolant 141is frozen and when the coolant 141 has melted. In the event the device100 loses coolant 141 over the course of time, the coolant vessel 140can include a fill/drain port 142. In a particular aspect of thisembodiment, the fill/drain port 142 can have a removable plug 148 thatis transparent, in addition to or in lieu of the coolant vessel 140being transparent. Similarly, the heat transfer fluid 155 can includeconstituents that change color when the heat transfer fluid attains atemperature that is no longer suitable for properly chilling the tissue110. The applicator 120 and/or the heat transfer conduit 150 (orportions thereof) can be made transparent to allow the user to easilydetermine when this temperature threshold has been exceeded.

Both the coolant 141 and the heat transfer fluid 155 are selected to behighly thermally conductive. Suitable constituents for the coolant 141include water in combination with propylene glycol, ethylene glycol,glycerin, ethanol, isopropyl alcohol, hydroxyethyl cellulose, salt,and/or other constituents. In at least some embodiments, the sameconstituents can be used for the heat transfer fluid 155, but the ratiosof the constituents (and therefore the overall composition of the heattransfer fluid) are selected to produce a lower liquid/solid phasetransition temperature. Both the heat transfer fluid 155 and the coolant141 can be selected to have high heat conductivity and low toxicity incase of a leak. Both can include an anti-microbial agent to restrict orprevent algae formulation and/or propagation of other undesirable lifeforms. The coolant 141 can be selected to have a high heat capacity tobetter absorb heat from the heat transfer fluid 155. The heat transferfluid 155 can have a relatively low heat capacity so that it readilyheats up when the heater 152 is activated. The heat transfer fluid 155can also be selected to have a low viscosity at operating temperaturesto facilitate flow through the heat transfer conduit 150, the heatexchanger 160 and the applicator 120. In any of these embodiments thecoolant vessel 140 in which the coolant 141 is disposed can be flexibleand elastic, and/or can include a vent or other feature to accommodatevolume changes as the coolant 141 changes phase.

FIG. 3 is a partially schematic, isometric illustration of an embodimentof the device 100 described above with reference to FIG. 2. As shown inFIG. 3, the applicator 120 has a generally flexible configuration,allowing it to conform to the shape of the tissue to which it isapplied. An attachment device 123 releaseably attaches the applicator120 to the tissue and can accordingly include a strap (e.g. Velcro), acuff (e.g., generally similar to a blood pressure cuff) or anothersuitable device. The coolant vessel 140 is housed in a coolant vesselhousing 143 that is in turn attached to or otherwise includes thesupport structure 121. The support structure 121 can be at leastpartially flexible so that when it is attached to the applicator 120, itdoes not overly inhibit the ability of the applicator 120 to conform tothe human tissue. In one embodiment, the support structure 121 and thecoolant vessel housing 143 can be supported relative to the applicator120 with standoffs. In another embodiment, an optional foam or otherflexible layer (e.g. an inflatable air bladder) 122 can be positionedbetween the support structure 121 and the applicator 120 to furtherfacilitate the ability of the applicator 120 to flex relative to thecoolant vessel housing 143.

In one aspect of an embodiment shown in FIG. 3, the power cord 173 canbe releasably attached directly to the pump motor 172, thus allowing thepower cord 173 to be removed before the device 100 is placed in thefreezer. The power cord 173 can be connected directly to an AC outlet,and can include a DC converter if the pump motor 172 is a DC motor. Ifthe pump motor 172 is coupled to a rechargeable battery located withinthe housing 143, the power cord 173 can be used to recharge the battery.

In another aspect of this embodiment, the pump motor 172 itself can beremoved from the coolant vessel housing 143, along with the power cord173, generally in the manner described above with reference to FIG. 2.In still a further particular aspect of this embodiment, the controller180 (not visible in FIG. 3) and associated output device 185 can becarried by the pump motor 172 and can accordingly be readily removedfrom the coolant vessel housing 143 along with the pump motor 172.

One feature of particular embodiments of the device 100 described abovewith reference to the FIGS. 1-3 is that the applicator 120, the coolantvessel 140, the heat exchanger 160, and the heat transfer conduit 150can be configured as an inseparable unit (at least during normaluse—components may be separated by an authorized servicer if necessaryduring a maintenance or repair process). Accordingly, these componentsform a sealed, closed-loop path for the heat transfer fluid 155. Anadvantage of this feature is that it is simple to use. In particular,the user can place the entire device 100 (or at least the abovecomponents) in the freezer or other cold environment until the coolant141 is frozen, and can remove the entire device 100 as a unit from thefreezer or other cold environment prior to cooling the target tissue.Because the arrangement is simple to use, it can be particularlysuitable for home use. Because it does not include removable components(in certain embodiments) or separable fluid connections, it is expectedto be more robust than systems that do include such features. Becausethe coolant 141 has a fixed liquid/solid phase transition temperature,the device 100 can easily control the temperature of the heat transferfluid 155 with a reduced level of active control, and the device 100 canbe thermally recharged in any environment having a temperature less thanthe phase transition temperature.

Another feature of particular embodiments of the device 100 describedabove is that the volume of heat transfer fluid 155 contained in thesystem can be made relatively low by using short lengths and/or smalldiameters for the heat transfer conduit 150 and the heat exchangertubing 161, and a low (e.g., thin) profile for the applicator 120.Accordingly, the coolant 141 can more quickly cool the heat transferfluid 155 and the entirety of the effective heat transfer surface of theapplicator 120. Having a low thermal mass for the heat transfer fluid155 will also reduce the amount of time and/or energy required toelevate the temperature of the applicator 120 to a comfortable levelafter the device 100 has been removed from the freezer.

Still another feature of particular embodiments of the device 100described above is that the unitary arrangement of the device isexpected to produce a compact size and therefore low mass. Thesefeatures in turn can make it easier to position the device in a freezer(e.g., a domestic freezer), and can make the device more comfortable andconvenient to wear during use.

Yet another feature of at least some of the foregoing embodiments isthat the simplicity of the device can reduce manufacturing costs andtherefore the costs to the user. In at least some instances, the deviceneed not include the serviceable component features described abovebecause the device may be cheaper to replace than repair. The device caninclude an automated lock-out or shut-down feature that activates aftera predetermined number of uses to prevent use beyond an expected periodof threshold efficacy or useful life.

3. Representative Devices and Methods that Include Separable CoolantVessels

FIG. 4 is a partially schematic, partially cut-away illustration of anembodiment of a device 400 having a user-removable or separable coolantvessel 440, unlike the configurations described above with reference toFIGS. 1-3. In particular, the device 400 can include a heat exchanger460 having a heat exchanger conduit (e.g., tubing) 461 positionedexternal to the coolant vessel 440, allowing the coolant vessel 440 tobe removed from the device 400 (as indicated by arrow D) for thermalrecharging or regeneration. Accordingly, the coolant vessel 440 can beplaced in a cold environment (e.g., a freezer) to re-cool (e.g.,re-freeze) the coolant 141, without placing the entire device 400 in thecold environment. This arrangement may be suitable for applications inwhich freezer space is limited and thus placing only the coolant vessel440 in the freezer is advantageous. As a result, certain aspects of thedevice 400 can be simpler than the device 100 described above withreference to FIGS. 1-3. For example, the heat transfer conduit 150 isnot cooled along with the coolant vessel 440 and accordingly the needfor the heater 152 and/or shunt channel 153 and shunt valves 154described above with reference to FIG. 2 can be eliminated. Conversely,an advantage of the arrangement described above with reference to FIGS.1-3 is that the interface between heat exchanger tubing 161 and thecoolant vessel 140 need not be disturbed when the coolant vessel 140 ischilled. As described further below with reference to FIGS. 5A-6B,certain aspects of the device 400 are designed to mitigate the potentialimpact of detaching and reattaching the heat exchanger 460 and thecoolant vessel 440.

FIG. 5A is an enlarged, partially schematic illustration of anembodiment of the coolant vessel 440 and the heat exchanger 460 in whichthe heat exchanger tubing 461 is positioned around the outside of thecoolant vessel 440. In particular, the heat exchanger tubing 461 canhave a serpentine shape extending upwardly and downwardly along thelongitudinal axis of the coolant vessel 440. The heat transfer fluid 155passes through the heat transfer tubing 461 as indicated by arrows E. Toremove the coolant vessel 440 from the heat exchanger 460, the userpulls the coolant vessel 440 upwardly as indicated by arrow D in FIG.5A. The heat exchanger tubing 461 can be “springy” and can accordinglybe resiliently biased inwardly toward the coolant vessel 440 toreleasably secure the coolant vessel 440 in position, and to provideintimate thermal contact between the heat exchanger tubing 461 and theexterior surface of the coolant vessel 440. This feature can alsopromote a “scrubbing” mechanical contact between the heat exchangertubing 461 and the exterior surface of the coolant vessel 440 to removefrost build-up or other residue to ensure good thermal contact as thesecomponents are connected. Further details of the foregoing arrangementare described below with reference to FIG. 5B.

FIG. 5B is a partially schematic, cross-sectional illustration of theheat exchanger 460 and the coolant vessel 440, taken substantially alongline 5B-5B of FIG. 5A. As shown in FIG. 5B, the coolant vessel 440 canhave an outer surface with a series of recesses 449, each of which issized and positioned to receive a portion of the heat exchanger tubing461. The exterior surface of the coolant vessel 440 can include a firstthermally conductive surface 462 a that is in intimate thermal andphysical contact with a corresponding second thermally conductivesurface 462 b of the heat exchanger tubing 461. Accordingly, thisarrangement can readily transfer heat between the heat transfer fluid155 within the heat exchanger tubing 461, and the coolant 141 within thecoolant vessel 440. The coolant vessel 440 can include features foruniformly distributing the liquid portion of the coolant 141 (e.g.,agitators) in a manner generally similar to that described above withreference to FIG. 2.

FIGS. 6A and 6B illustrate another arrangement of a coolant vessel 640that is removably attached to a corresponding heat exchanger 660 inaccordance with another embodiment of the technology. In one aspect ofthis embodiment, the coolant vessel 640 includes multiple verticallyextending blind channels 644 defined at least in part by a thermallyconductive channel wall 645. The heat exchanger 660 includes thermallyconductive heat exchanger tubing 661 that directs the heat transferfluid 155 into and out of the blind channels 644. In particular, theheat exchanger tubing 661 can include supply sections 664 a that extendinto the blind channels 644 and are coupled to a supply manifold 663 a.The heat exchanger tubing 661 can further include corresponding returnsections 664 b that also extend into each of the blind channels 644 andare coupled to a return manifold 663 b. In a particular embodiment, thereturn sections 664 b are located annularly inwardly within thecorresponding supply sections 664 a. Accordingly, the heat transferfluid enters the supply sections 664 a, rises within the blind channels664 and then descends through the return sections 664 b, as indicated byarrows E. The coolant vessel 640 is removed from the heat exchanger 660by pulling it upwardly away from the heat exchanger 660 as indicated byarrow D, and is replaced by placing it downwardly over the heatexchanger 660, with the blind channels 644 aligned with thecorresponding supply sections 664 a. The blind channels 644 and thecorresponding supply sections 664 a can be tapered and/or otherwisebiased into contact with each other to promote thermal contact and tofacilitate mechanically scraping frost from surfaces of either element.

FIG. 6B is a partially schematic, cross-sectional illustration of thecoolant vessel 640 and the heat exchanger 660, taken substantially alongline 6B-6B of FIG. 6A. As shown in FIG. 6B, the blind channels 664include thermally conductive channel walls 665 that are in intimatethermal contact with the outer surfaces of the supply sections 664 a.Arrows E indicate the radially inward path of the heat transfer fluid155 as it moves from the supply sections 664 a to the return sections664 b.

4. Representative Devices and Methods that Include Separable CoolantVessels and Heat Exchangers

FIG. 7 is a partially schematic, partially cut-away illustration of adevice 700 having a releasable coupling 756 between a heat exchanger 760and a coolant vessel 740 on one hand, and the heat transfer conduit 150on the other. Accordingly, the releasable coupling 756 can include asupply coupling 757 a at the supply portion 151 a of the heat transferconduit 150, and a return coupling 757 b at the return portion 151 b ofthe heat transfer conduit 150. The couplings 757 a, 757 b can includeany suitable fluid-tight, easily releasable and reattachable elements.For example, the couplings 757 a, 757 b can include quick-releasecouplings generally similar to those used for intravenous fluidconnections.

One feature of an embodiment shown in FIG. 7 is that, like theembodiments described above with reference to FIGS. 4-6B, the entiredevice 700 need not be placed in the freezer or other cold environmentto re-solidify or otherwise re-cool the coolant 141. In addition, thedevice 700 does not require that the thermal connection between the heatexchanger 760 and the coolant vessel 740 be disturbed in order torecharge the coolant vessel 740. Conversely, an advantage of thearrangements described above with reference to FIGS. 1-6B is that theydo not require connecting and disconnecting fluid conduits.

FIG. 8 is a partially schematic, cross-sectional illustration of aportion of the heat exchanger 760 and the coolant vessel 740, takensubstantially along line 8-8 of FIG. 7. As shown in FIG. 8, the coolantvessel 740 can include a vessel wall 746 having an insulative portion747 a over a portion of its surface, and a conductive portion 747 b inareas adjacent to the heat exchanger tubing 761. For example, theinsulative portion 747 a can include a material such as a plastic thathas a low thermal conductivity to prevent or at least restrict heattransfer to the coolant vessel 740 except as it is received from theheat exchanger tubing 761. The conductive portion 747 b can includecopper or another highly thermally conductive material that readilytransfers heat between the coolant 141 and the heat exchanger tubing761, which can also include copper or another highly thermallyconductive material. The heat exchanger tubing 761 can be welded to orotherwise intimately bonded to the conductive portion 747 b in a waythat provides high thermal conductivity between the two. In otherembodiments, the heat exchanger tubing 761 can take the form of achannel that is integrally formed with the conductive portion 747 b,e.g., in a casting process.

When the coolant 141 is selected to undergo a phase change duringoperation, it can include a solid component 141 a generally positionedaway from the vessel wall 746 once the coolant 141 begins to melt, and aliquid component 141 b generally in contact with the inner surface ofthe vessel wall 746 and conductive portion o the vessel wall 747 b. Asdescribed above, the coolant vessel 740 can include an agitator or otherdevice to enhance the uniform distribution of heat transfer within thecoolant vessel 740 by circulating the liquid component 141 b, moving thesolid component 141 a, and/or vibrating or otherwise moving the coolantvessel 740.

5. Representative Applicators and Associated Methods

FIGS. 9-11 illustrate particular features of applicators that may form aportion of any of the devices described above with reference to FIGS.1-8. In other embodiments, these applicators may be used with devicesother than those expressly shown and described above with reference toFIGS. 1-8. The size and shape of the applicator can be selected based onthe user's physiology and the location on the user's body to which theapplicator will be attached.

FIG. 9 illustrates an applicator 920 that includes an envelope 924having an entry port 928 a coupled to a heat transfer fluid supplyportion 151 a, and an exit port 928 b coupled to a return portion 151 b.The envelope 924 can include a flexible first portion 925 in contactwith the human tissue 110, and a flexible second portion 926 facing awayfrom the human tissue 110. The flexible first portion 925 can beattached to the flexible second portion 926 at corresponding bonds 927formed by an adhesive, thermal welding, or other suitable process. Thefirst portion 925 has a first elasticity, and the second portion 926 hasa second elasticity less than the first elasticity. Accordingly, thesecond portion 926 can, in at least some embodiments, be non-elastic. Asused herein, the term “non-elastic” applies to a material that does notstretch, or stretches by only an insignificant amount when theapplicator 920 is subjected to normal operating pressures. The term“elastic” as used herein applies to a material that does stretch whenthe applicator is subjected to normal operating pressures provided bythe attachment of the device to the patient and/or heat transfer fluid155. Because the first portion 925 is more elastic than the secondportion 926, it can readily conform to the local shape of the humantissue 110. In particular, the first portion 925 can conform to theunderlying tissue 110 without forming creases 930 (shown in dotted linesin FIG. 9), which form in some existing devices and can interfere withskin/applicator thermal contact and/or internal flow within theapplicator 920. As a result, the first portion 925 is more likely toremain in close thermal contact with the human tissue 110 and cantherefore more efficiently transfer heat away from the tissue 110. Thesecond portion 926 can flex in a manner that accommodates the contour ofthe human tissue 110, without stretching at all, or without stretchingin a manner that might cause the envelope to bulge outwardly away fromthe tissue 110 (e.g., at the ends of the applicator 920) and therebyreduce the degree of thermal contact between the envelope 924 (and moreparticularly, the heat transfer fluid 155) and the tissue 110.

In particular embodiments, the second portion 926 can includepolyethylene, polypropylene, nylon, vinyl, and/or another suitableplastic film. The first portion 925 can include latex rubber, nitrile,polyisoprene and/or urethane, and/or another suitable elastomericmaterial. An optional elastic mesh 929 can be positioned adjacent to thefirst portion 925 (or the entire envelope 924), and can include anelastic nylon, rubber and/or other suitable elastic material. The mesh929 can prevent the first portion 925 from undergoing excessive wearand/or bulging during handling. It can accordingly be strong, but thinenough to avoid significantly interfering with the heat transfer processbetween the applicator 920 and the tissue 110.

In a particular embodiment, the applicator 920 can also include aflexible support structure 921 that provides additional support for theenvelope 924, without inhibiting the ability of the envelope 924 toconform to the tissue 110. The support structure 921 can also functionas the releasable coupling (e.g., a cuff) securing the applicator 920 tothe tissue 110. In any of these embodiments, the support structure 921can have a pre-formed shape (e.g., a downwardly-facing concave shape)and can be resiliently biased toward the pre-formed shape. Accordingly,the applicator 920 can more readily conform to a convex tissue surface.In particular embodiments, a family of applicators having differentshapes can be coupled to a similar type of overall cooling device toprovide for system commonality and interchangeability.

FIG. 10 is a partially schematic, cross-sectional illustration of anapplicator 1020 having an envelope 1024, an external support structure1021 a generally similar to that described above with reference to FIG.9, and an internal support structure 1021 b located within the envelope1024. The internal support structure 1021 b can be porous, e.g., 50%porosity or higher in some embodiments, and in particular embodiments,in the range of from about 75% porosity to about 95% porosity.Accordingly, the internal support structure 1021 b can diffuse the heattransfer fluid 155 throughout the envelope 1024 from an entry port 1028a to an exit port 1028 b, without overly restricting the flow of theheat transfer fluid 155. The particular porosity value selected for theinternal support structure 1021 b can depend on factors that include theviscosity and/or flow rate of the heat transfer fluid 155. In aparticular embodiment, the internal support structure 1021 b can includea porous matrix material having one or multiple layers 1031 (three areshown in FIG. 10 for purposes of illustration) that can slide relativeto each other, as indicated by arrows F. In a further particularembodiment, the internal support structure 1021 b is attached to theinner surfaces of the envelope 1024 to prevent the envelope from overlystretching. The envelope 1024 can also include spaced-apart connections1035 (e.g., stitches or perforated panels) that extend from the envelopeupper surface through the internal support structure 1021 b to theenvelope lower surface to prevent or restrict the envelope 1024 fromballooning when pressurized with the heat transfer fluid 155 whileallowing the layers 1031 to slide laterally relative to each other.Accordingly, when the applicator 1020 is coupled to an upstream fluiddriver 1070 a, the pressure exerted by the incoming heat transfer fluid155 on the envelope 1024 will be less likely to expand the envelope1024.

The internal support structure 1021 b can resist buckling, in additionto or in lieu of resisting bulging or ballooning. For example, theinternal support structure 1021 b can have a high enough bucklingstrength so that when the applicator 1020 is coupled to a downstreamfluid driver 1070 b, the envelope 1024 will not collapse upon itself dueto external, ambient pressure (e.g., to the point that it inhibits theflow of heat transfer fluid 155) when the heat transfer fluid 155 iswithdrawn through the exit port 1028 b. In particular embodiments, theheat transfer fluid 155 may be withdrawn via a pressure that is up toabout 2 psi below the pressure outside the envelope 1024. In otherembodiments, the foregoing pressure differential can be up to about 5psi or 10 psi without the envelope 1024 collapsing on itself. This willhelp keep the envelope from ballooning due to positive internalpressure. Another advantage of the downstream fluid driver 1070 b isthat if the envelope 1024 is inadvertently punctured, the downstreamfluid driver 1070 b will suck air through the puncture, while theupstream fluid driver 1070 a will continue to pump heat transfer fluid155 through such a puncture.

FIG. 11 is a partially schematic, enlarged illustration of a portion ofthe applicator 1020 circled in FIG. 10. As shown in FIG. 11, theinternal support structure 1021 b can include small pores 1034distributed throughout the structure. At the interface with the tissue110, the pores can form a distributed arrangement of generallyhemispherical dimples. When the envelope 1024 includes a material thatis not elastic, the material will tend to crease when folded over aconvex portion of the tissue 110. The pores 1034 are small enough sothat they accommodate or receive small “microcreases” 1033 that can formalong the surface of the envelope 1024. Unlike the creases 930 describedabove with reference to FIG. 9, the microcreases 1033 are very small andaccordingly do not significantly inhibit the internal flow within theapplicator and do not significantly disrupt the uniformity of the heattransfer between the heat transfer fluid 155 within the envelope 1024,and the tissue 110 outside the envelope 1024. In effect, themicrocreases 1033 can distribute the creasing effect of the envelopematerial over a larger area that reduces the overall impact of theeffect on fluid flow and heat transfer. In particular embodiments, themicrocreases 1033 can have a generally hemispherical shape that ispre-set into the envelope material using a thermoset process. In otherembodiments, the shape and/or formation process of the microcreases 1033can be different. In still another embodiment, the entire portion of theenvelope 1024 in contact with the patient tissue can have a pre-set orpre-formed shape (e.g., a hemispherical or other concave shape) that ismaintained as the envelope is placed in contact with the patient tissue;

In a particular embodiment, the internal support structure 1021 b caninclude a TN Blue non-abrasive non-woven polyester pad available fromGlit/Microtron. This material can be made in multiple layers (e.g., twolayers, each 0.35 of an inch thick) encased in a polyether-polyurethanefilm envelope 1024 having a thickness of 0.006-0.012 inches. Theinternal support structure 1021 b, which is already porous due to thefibrous make-up of the material, can be even further perforated with ahole pattern, producing small diameter holes spaced uniformly spacedapart, and oriented generally perpendicular to the major surfaces of theenvelope 1024. These holes can facilitate bending the internal supportstructure 1021 b to conform to convex and/or concave shapes. It isexpected that the relatively thin overall dimensions of the resultingapplicator 1020 (e.g., from about 0.25 inch to about 0.50 inch) willallow the applicator 1020 to readily conform to the human anatomy. Thelow flow impedance of the internal support structure 1021 b is expectedto allow flow rates of approximately 0.1 to 5 liters per minute,suitable for adequately cooling the adjacent tissue. In addition, thethree-dimensional nature of the fibrous, porous structure can facilitatea uniform distribution of the heat transfer fluid 155 within theapplicator 1020, producing a more uniform treatment of the adjacenttissue 110.

The porosity of the internal support structure 1021 b can vary from oneportion of the applicator 1020 to another, and/or can vary dependingupon the local flow direction desired for the heat transfer fluid 155.For example, the porosity of the internal support structure 1021 b canbe selected to enhance heat transfer from the tissue in the peripheralareas of the applicator 1020, e.g., to account for the expected increasein heat transfer losses to the ambient environment in these areas. Theporosity can be altered by adjusting the number and/or size of the poreswithin the internal support structure 1021 b, as well as the spatialorientation of the pores.

From the foregoing, it will be appreciated that specific embodiments ofthe technology have been described herein for purposes of illustration,but that various modifications can be made without deviating from thetechnology. For example, the devices described above can includecomponents that provide mechanical energy to create a vibratory, massageand/or pulsatile effect in addition to cooling the subcutaneous tissue.Representative components are described in U.S. Pat. No. 7,367,341 andin commonly assigned U.S. Patent Publication No. 2008/0287839, both ofwhich are incorporated herein by reference. While certain features ofthe devices described above make them particularly suitable for homeuse, such features do not preclude the devices from being used inhospital or clinical office settings. In such embodiments, the devicesor portions of the devices can be cooled in commercial, clinical orinstitutional freezers and/or coolers. The shapes, sizes andcompositions of many of the components described above can be differentthan those disclosed above so long as they provide the same or generallysimilar functionalities. For example, the conduits and tubing describedabove can have other shapes or arrangements that neverthelesseffectively convey fluid. The fluid driver can be operatively coupled tothe heat transfer conduit without being directly connected to the heattransfer conduit, e.g., by being connected to the heat exchanger thatconveys the heat transfer fluid, or by being connected to theapplicator. The controller can implement control schemes other thanthose specifically described above, and/or can be coupled to sensorsother than those specifically described above (e.g., pressure sensors)in addition to or in lieu of temperature and time sensors, to detectchanges associated with the cooling device. The controller can in somecases accept user inputs, though in most cases, the controller canoperate autonomously to simplify the use of the device. As discussedabove, the coolant in some embodiments can go through a phase changeduring heating and cooling, so that the cooling process freezes orsolidifies the coolant. In other embodiments for which no phase changeoccurs, the cooling process does not freeze or solidify the coolant.

Certain aspects of the technology described in the context of particularembodiments may be combined or eliminated in other embodiments. Forexample, the applicators described above in the content of FIGS. 9-11can be used with any of the devices described above with reference toFIGS. 1-8. The thermal connections between the heat exchanger tubing andthe coolant vessel described in the content of FIG. 8 can be applied tothe arrangement shown and described in the content of FIGS. 1-3. Theheaters and flow agitators described in the context of certainembodiments can be eliminated in other embodiments. Further, whileadvantages associated with certain embodiments of the technology havebeen described within the context of those embodiments, otherembodiments may also exhibit such advantages, and not all embodimentsneed necessarily exhibit such advantages to fall within the scope of thepresent disclosure. Accordingly, the present disclosure and associatedtechnology can encompass other embodiments not expressly shown ordescribed herein.

We claim:
 1. A cooling device for cooling subcutaneous lipid-rich cellsin a human, comprising: an applicator releasably positionable againsthuman skin, the applicator including: a flexible, fluid-tight envelopehaving an entry port, an exit port, a fluid chamber, and first andsecond oppositely-facing internal surfaces positioned on opposite sidesof the fluid chamber; and a porous internal structure positioned withinthe envelope between the entry port and the exit port, positioneddirectly between the first and second internal surfaces of the envelope,and positioned throughout substantially the entire fluid chamber, theinternal structure including multiple layers of fibrous materialpositioned face-to-face such that the layers of fibrous materialslidably contact one another along substantially an entire length of theporous internal structure when the flexible, fluid-tight envelope iscompletely filled with a pressurized fluid, the internal structure: (a)having a buckling strength sufficient to prevent the envelope fromcollapsing on itself when the outlet port is exposed to a pressure belowa pressure external to the envelope, and (b) being attached to an innersurface of the envelope to at least restrict the envelope from bulgingwhen a pressurized fluid is applied to an entry port.
 2. The device ofclaim 1 wherein the internal structure has a buckling strengthsufficient to prevent the envelope from collapsing on itself when theoutlet port is exposed to a pressure of up to 2 psi below a pressureexternal to the envelope.
 3. The device of claim 1 wherein the internalstructure has a buckling strength sufficient to prevent the envelopefrom collapsing on itself when the outlet port is exposed to a pressureof up to 5 psi below a pressure external to the envelope.
 4. A coolingdevice for cooling subcutaneous lipid-rich cells in a human, comprising:an applicator releasably positionable against human skin, the applicatorincluding: a flexible, fluid-tight envelope having an entry port, anexit port, a fluid chamber, and first and second oppositely-facinginternal surfaces positioned on opposite sides of the fluid chamber; anda porous internal structure positioned within the envelope between theentry port and the exit port, positioned directly between the first andsecond internal surfaces of the envelope, and positioned throughoutsubstantially the entire fluid chamber, the internal structure includinglayers of fibrous material in a face-to-face arrangement such that thelayers of fibrous material slidably contact one another oversubstantially an entire length of the porous internal structure when theflexible, fluid-tight envelope is filled with a pressurized fluid, theporous internal structure: (a) having a buckling strength sufficient toprevent the envelope from collapsing on itself when the outlet port isexposed to a pressure below a pressure external to the envelope, whereinthe internal structure has a buckling strength sufficient to prevent theenvelope from collapsing on itself when the outlet port is exposed to apressure of up to 10 psi below a pressure external to the envelope, and(b) being attached to an inner surface of the envelope to at leastrestrict the envelope from bulging when a pressurized fluid is appliedto an entry port.
 5. A cooling device for cooling subcutaneouslipid-rich cells in a human, comprising: an applicator releasablypositionable against human skin, the applicator including: a flexible,fluid-tight envelope having an entry port, an exit port, and a fluidholding chamber; and a porous internal structure positioned within thefluid holding chamber and located between the entry port and the exitport, wherein the internal structure includes multiple layers of fibrousmaterial positioned face-to-face such that the layers of fibrousmaterial slidably contact one another along substantially an entirelength of the porous internal structure when the envelope is completelyfilled with a pressurized fluid, the internal structure: (a) having abuckling strength sufficient to prevent the envelope from collapsing onitself when the outlet port is exposed to a pressure below a pressureexternal to the envelope, and (b) being attached to an inner surface ofthe envelope to at least restrict the envelope from bulging when thepressurized fluid is applied to an entry port.
 6. The device of claim 1wherein the applicator further comprises attachment elements extendingfrom the first internal surface to the second internal surface.
 7. Thedevice of claim 1, further comprising: a heat exchanger operably coupledto the applicator; and a pump having an inlet coupled to the exit portof the applicator to draw fluid from the applicator, and an outletupstream of the heat exchanger.
 8. The device of claim 1, furthercomprising: a heat exchanger operably coupled to the applicator; and apump having an outlet coupled to the entry port of the applicator topump fluid into the applicator, and an inlet downstream of the heatexchanger.
 9. The device of claim 1 wherein the envelope includes: afirst portion comprising a flexible first material positioned to beplaced against the skin and having a first elasticity; and a secondportion sealably connected to the first portion, the second portioncomprising a flexible second material facing away from the first portionand having a second elasticity less that the first elasticity, at leastone of the first and second portions being movable relative to the otherto accommodate the pressurized fluid therebetween.
 10. The device ofclaim 1 wherein a portion of the envelope that is positionable againsthuman skin has a pre-formed concave shape.
 11. The cooling device ofclaim 1, further comprising: a fluid driver fluidically coupled to theentry port, the exit port, and a heat exchanger, wherein the fluiddriver is configured to cause fluid that has been cooled by the heatexchanger to flow through the porous internal structure to remove heatfrom the subcutaneous lipid-rich cells via the applicator in an amountsufficient to selectively reduce the subcutaneous lipid-rich cells. 12.The cooling device of claim 1 wherein the fluid flows through the porousinternal structure to diffuse through the fluid chamber of the envelope.13. The cooling device of claim 1 wherein the porous internal structureis physically coupled to the first internal surface and is physicallycoupled to the second internal surface.
 14. The cooling device of claim1 wherein the porous internal structure has a porosity of 50% or higher.15. A cooling device for cooling subcutaneous lipid-rich cells in ahuman, comprising: an applicator configured to be positioned againsthuman skin, the applicator including: a flexible, fluid-tight envelopehaving an entry port, an exit port, and first and secondoppositely-facing internal surfaces; and an internal structure containedwithin the envelope and positioned directly between the first and secondinternal surfaces, the internal structure occupying a majority of avolume of a chamber in the envelope and configured to diffuse fluidthrough the chamber of the envelope, the internal structure includinglayers of fibrous material positioned face-to-face such that the layersof fibrous material slidably contact one another along substantially anentire length of the porous internal structure when the envelope iscompletely filled with a pressurized fluid, the internal structure: (a)having a sufficient buckling strength and being positioned to preventcontact between opposing inner surfaces of the envelope when the outletport is exposed to a pressure below a pressure external to the envelopeand fluid flows through the internal structure, and (b) being attachedto an inner surface of the envelope to at least restrict the envelopefrom bulging when fluid applied to an entry port is pressurized.
 16. Acooling device for cooling subcutaneous lipid-rich cells in a human,comprising: an applicator configured to be positioned against humanskin, the applicator including: a flexible, fluid-tight envelope havingan entry port, an exit port, and first and second oppositely-facinginternal surfaces; and an internal structure contained within theenvelope and positioned directly between the first and second internalsurfaces, the internal structure occupying a majority of a volume of achamber in the envelope and configured to diffuse fluid through thechamber of the envelope, the internal structure: (a) having a sufficientbuckling strength and being positioned to prevent contact betweenopposing inner surfaces of the envelope when the outlet port is exposedto a pressure below a pressure external to the envelope and fluid flowsthrough the internal structure, and (b) being attached to an innersurface of the envelope to at least restrict the envelope from bulgingwhen fluid applied to an entry port is pressurized, a heat exchanger;and a fluid driver fluidically coupled to the entry port, the exit port,and the heat exchanger, wherein the internal structure is porous, andwherein the fluid driver is configured to cause fluid that has beencooled by the heat exchanger to travel through the porous internalstructure and to remove heat from subcutaneous lipid-rich tissue in ahuman via the applicator in an amount sufficient to selectively reducethe subcutaneous lipid-rich cells.
 17. The cooling device of claim 15wherein the internal structure is physically connected to the firstinternal surface and physically coupled to the second internal surface.18. The cooling device of claim 15 wherein the internal structure has aporosity of 50% or higher.
 19. The cooling device of claim 15 whereinthe internal structure is located throughout most of a chamber of theenvelope when the envelope is filled with fluid.
 20. The cooling deviceof claim 15 wherein the internal structure extends across most of adistance between the entry port and the exit port when the envelope isfilled with fluid.
 21. The cooling device of claim 1 wherein theinternal structure is positioned throughout most of the fluid chamber ofthe envelope such that the internal structure distributes fluid flowingthrough the fluid chamber to promote uniform cooling of tissue adjacentthe applicator.
 22. The cooling device of claim 1 wherein the internalstructure is positioned throughout most of the fluid chamber of theenvelope when the envelope is filled with fluid.
 23. A cooling devicefor cooling subcutaneous lipid-rich cells in a human, comprising: anapplicator releasably positionable against human skin, the applicatorincluding: a flexible, fluid-tight envelope having an entry port, anexit port, a first surface, and a second surface; and a porous internalstructure positioned within the envelope between the entry port and theexit port and directly between the first and second surfaces, whereinthe internal structure includes multiple layers of fibrous materialpositioned face-to-face such that the layers of fibrous materialslidably contact each other along substantially an entire length of theporous internal structure when the envelope is filled with fluid, andwherein at least one of the multiple layers is slidable relative to theenvelope when the envelope is filled with the fluid, the internalstructure having a buckling strength sufficient to prevent the envelopefrom collapsing on itself when the outlet port is exposed to a pressurebelow a pressure external to the envelope.